Air conditioner and method of controlling air conditioner

ABSTRACT

An air conditioner is provided that can reduce the occurrence of situations in which the comfort level of an occupant of a room is degraded. The air conditioner is capable of running in cooling mode and/or dehumidifying mode and is provided with an air delivery unit, a flap, and a control unit. The air delivery unit delivers conditioned air into the room. The flap determines the discharge direction of the air delivered from the air delivery unit. The control unit executes a first control that changes the swing speed of the flap in accordance with the room temperature.

TECHNICAL FIELD

The present invention relates to an air conditioner and a control methodfor controlling an air conditioner. More particularly, the presentinvention relates to an air conditioner capable of running in coolingmode and/or dehumidifying mode and a control method for controlling thesame air conditioner.

BACKGROUND ART

Air conditioners that are installed in homes and office buildings andserve to improve the comfort level in a room by delivering conditionedair into the room are a known conventional technology. These airconditioners maintain a room temperature that is comfortable for theoccupants by delivering cool air or warm air into the room, thusimproving the comfort level of the room.

These air conditioners are provided with a flap for determining thedischarge direction of the air that is delivered after beingconditioned. The flap is often swung at a constant speed in order todeliver the conditioned air to all corners of the room. Since the flapswing speed of these air conditioners is constant, the amount of timethat the delivered air flow contacts the room occupants during eachswing is always the same. When the room temperature is comparativelyhigh, it is possible for an occupant to feel that the room is hotbecause the same amount of air constantly contacts the occupant. Whenthe room temperature is comparatively low, it is possible for anoccupant to feel that the room is cold because the same amount of airconstantly contacts the occupant. Thus, with conventional airconditioners, there are times when the occupants of the room feeluncomfortable during cooling mode and dehumidifying mode.

SUMMARY OF THE INVENTION

The object of this invention is to provide an air conditioner that canreduce the occurrence of situations in which the comfort level of theroom occupants is degraded.

According to a first aspect of the present invention, an air conditionerthat is capable of running in cooling mode and/or dehumidifying mode isprovided with an air delivery unit, a flap, and a control unit. The flapdetermines the discharge direction of the air delivered from the airdelivery unit. The control unit executes a first control to change theswing speed of the flap in accordance with the room temperature.

With this air conditioner, the air inside the room is conditioned insidethe air conditioner. The direction in which the air is discharged isdetermined by the flap. The swing speed of the flap is changed by thecontrol unit according to the room temperature.

Since the swing speed of the flap is changed according to the roomtemperature, i.e., since the amount of time the delivered air contactsan occupant during each swing (complete swing including return swing) ischanged according to the room temperature, the occurrence of situationsin which the comfort level of the room occupants is degraded can bereduced by appropriately setting the room temperatures at which theswing speed is changed and the speed values to which the swing speed ischanged.

According to a second aspect of the present invention, the airconditioner of the first aspect of the present invention is provided,wherein the control unit changes the swing speed to a first swing speedwhen the room temperature is equal to or above a prescribed temperature.When the room temperature below the prescribed temperature, the controlunit changes the swing speed to a second swing speed. The first swingspeed is slower than the second swing speed.

Thus, when the room temperature is equal to or above the prescribedtemperature, the flap is swung at a slower speed than when the roomtemperature is below the prescribed temperature. Likewise, the amount oftime the delivered air contacts the body of an occupant during one swingof the flap is longer when the room temperature is equal to or above theprescribed temperature than when the room temperature is below theprescribed temperature. When the room temperature is equal to or abovethe prescribed temperature, the sensible temperature experienced by theroom occupants decreases because the air delivered from the airconditioner contacts the room occupants for a long period of time. As aresult, the occurrence of situations in which the comfort level of theroom occupants is degraded is reduced. When the room temperature isbelow the prescribed temperature, the sensible temperature experiencedby the room occupants does not decrease too much because the airdelivered from the air conditioner contacts the occupants for only ashort period of time. As a result, the occurrence of situations in whichthe room occupants feel cold is reduced and the occurrence of situationsin which the comfort level of the room occupants is degraded is reducedeven further.

According to a third aspect of the present invention, the airconditioner of the second aspect of the present invention is provided,wherein the control unit can also execute a second control. The secondcontrol does not swing the flap. The air conditioner described in claim3 is also provided with a selecting means. The selecting means selectsbetween the first control and the second control.

Since either the first control or the second control is selected, thisair conditioner can fix the air discharge direction by selecting thesecond control so that the flap does not swing.

According to a fourth aspect of the present invention, the airconditioner of the third aspect of the present invention is provided,wherein the control unit can also execute a third control. The thirdcontrol swings the flap at a constant speed at all times. The selectingmeans selects among the first control, the second control, and the thirdcontrol.

Since either the first control, the second control, or the third controlis selected, this air conditioner can change the air discharge directionat a constant speed by selecting the third control, which swings theflap at a constant speed at all times.

According to a fifth aspect of the present invention, the airconditioner of any one of the first to fourth aspects of the presentinvention is provided, wherein the control unit swings the flap in anup-and-down direction.

Since the flap is swung up and down, the delivered air can be made tocontact the room occupants even when, for example, the air delivery unitis installed above the occupants' heads (ceiling, upper part of wall,etc.) by aiming the flap downward. In short, it is easy to make thedelivered air contact the room occupants.

According to a sixth aspect of the present invention, an air conditioneris provided with an air delivery unit for delivering conditioned airinto a room and a flap for determining the discharge direction of theair delivered from the air delivery unit and is capable of running incooling mode and/or dehumidifying mode. The air conditioner controlmethod includes a first step and a second step. In the first step, theroom temperature is measured. In the second step, the swing speed of theflap is changed according to the room temperature.

Since the swing speed of the flap is changed according to the roomtemperature, i.e., since the amount of time the delivered air contactsan occupant during each swing (complete swing including return swing) ischanged according to the room temperature, the occurrence of situationsin which the comfort level of the room occupants is degraded is reduced.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 shows the external appearance of an air conditioner in which anembodiment of the present invention has been employed.

FIG. 2 is a schematic view of the refrigerant circuit.

FIG. 3 is a cross sectional view of the indoor unit taken along line A—Aof FIG. 1.

FIG. 4 is an enlarged view of section B of FIG. 3 when the flap ishorizontal.

FIG. 5 is an enlarged view of section B of FIG. 3 when the flap isdirected downward.

FIG. 6 is an enlarged view of section B of FIG. 3 when the airconditioner is not running.

FIG. 7 is a block diagram of the control unit.

FIG. 8 is a block diagram of the ROM.

FIG. 9 is swing control flowchart for a horizontal flap during coolingmode and dehumidifying mode.

PREFERRED EMBODIMENTS OF THE INVENTION

Constituent Features of the Air Conditioner>

FIG. 1 shows the external appearance of an air conditioner 1 in which anembodiment of the present invention has been employed.

The air conditioner 1 is a device that delivers conditioned (i.e.,cooled, heated, dehumidified, etc.) air into a room to condition the airinside the room. The air conditioner 1 is provided with an indoor unit 2installed on an upper section of a wall inside the room and an outdoorunit 3 installed outdoors. The outdoor unit 3 is provided with anoutdoor air conditioning unit 5 that encloses an outdoor heat exchangerand an outdoor fan.

The indoor unit 2 encloses an indoor heat exchanger and the outdoor airconditioning unit 5 encloses an outdoor heat exchanger. These heatexchangers together with the refrigerant pipe 6 connecting themconstitute a refrigerant circuit.

The refrigerant circuit used in the air conditioner 1 is illustrated inthe flow diagram of FIG. 2.

The indoor heat exchanger 11 is provided inside the indoor unit 2. Theindoor heat exchanger 11 includes a heat exchanger tube that is foldedback a plurality of times in the lengthwise direction and a plurality offins through which the heat exchanger tube is passed. The indoor heatexchanger 11 exchanges heat with the air it contacts.

A cross flow fan 12 is also provided inside the indoor unit 2 and servesto blow the air that has exchanged heat with the indoor heat exchanger11 into the room. The cross flow fan 12 is cylindrical in shape and isprovided with blades arranged on its circumferential surface so as to beparallel to the rotational axis thereof. The cross flow fan 12 generatesan air flow in a direction that intersects with the rotational axis. Thecross flow fan 12 is rotationally driven by a fan motor 13 providedinside the indoor unit 2.

The outdoor air conditioning unit 5 is provided with a compressor 21, afour-way selector valve 22, an accumulator 23, an outdoor heat exchanger24, and a pressure reducer 25 (see FIG. 2). The four-way selector valve22 is connected to the discharge side of the compressor 21. Theaccumulator 23 is connected to the intake side of the compressor 21. Theoutdoor heat exchanger 24 is connected to the four-way selector valve22. The pressure reducer 25 is an electric powered expansion valveconnected to the outdoor heat exchanger 24. The pressure reducer 25 isconnected to a pipe 31 through a filter 26 and a liquid shut-off valve27 and, thus, is connected to one end of the indoor heat exchanger 11through the pipe 31. The four-way selector valve 22 is connected to apipe 32 through a gas shut-off valve 28 and, thus, is connected to theother end of the indoor heat exchanger 11 through the pipe 32. Thesepipes 31, 32 are equivalent to the refrigerant pipe 6 shown in FIG. 1.

A cross sectional view of the indoor unit 2 is shown in FIG. 3. Thepreviously described indoor heat exchanger 11 and the cross flow fan 12are housed inside the casing 14 of the indoor unit 2. The indoor heatexchanger 11 is arranged so as to surround the front, top, and upperrear portions of the cross flow fan 12. The cross flow fan 12 draws airinto the unit through intake openings 142. As the air moves toward thecross flow fan 12, it exchanges heat with the refrigerant inside theheat exchanger tube of the indoor heat exchanger 11.

A drain pan 141 is provided below the indoor heat exchanger 11 to catchwater droplets that form on the surface of the indoor heat exchanger 11during the process of exchanging heat. The drain pan 141 has a drainhose (not shown) for discharging the water droplets caught to theoutside. The drain pan 141 is constructed such that it catches waterdroplets and discharges the water droplets by means of the drain hose.

An intake opening 142 made up of a plurality of slit-shaped openings isprovided in an upper part of the casing 14. An outlet opening 143 thatis long in the lengthwise direction of the indoor unit 2 is provided ina lower part of the casing 14. A horizontal flap 144 for determining thedischarge direction of the air delivered into the room by the cross flowfan 12 is provided in the outlet opening 143. The horizontal flap 144can rotate freely about a shaft 145 that is parallel to the lengthwisedirection of the indoor unit 2. The horizontal flap 144 can determinethe discharge direction of the air by being rotated by a flap motor 146(see FIG. 7), which is described later. As shown in FIG. 4, theconditioned air is blown in an approximately horizontal direction whenthe edge part 144 a of the horizontal flap 144 points in anapproximately horizontal direction. As shown in FIG. 5, the conditionedair is blown in an approximately vertical downward direction when theedge part 144 a of the horizontal flap 144 points in an approximatelyvertical downward direction. As shown in FIG. 6, the edge part 144 a ofthe horizontal flap 144 touches an edge part of the casing 14 when theair conditioner 1 is not running. In this state, the horizontal flap 144covers the outlet opening 143 almost completely.

Inside the outdoor air conditioning unit 5 is provided a propeller fan29 for discharging air to the outside after the air has exchanged heatwith the outdoor heat exchanger 24. The propeller fan 29 is rotationallydriven by a propeller fan motor 30.

<Control Unit>

The air conditioner 1 is also provided with a control unit 60. As shownin FIG. 7, the control unit 60 is connected to the compressor 21, thefour-way selector valve 22, the pressure reducer 25, a ROM 41, a RAM 42,the fan motor 13, the flap motor 146, a remote control 40, and atemperature sensor 43. The control unit 60 executes control of thepressure reducer 21, the four-way selector valve 22, the pressurereducer 25, the fan motor 13, the flap motor 146, etc.

The ROM 41 stores control programs and various parameters. The ROM 41also stores the swing speed settings and swing modes of the horizontalflap 144 (see FIG. 8).

The swing speed settings are operating speeds for determining the swingspeed of the horizontal flap 144. More specifically, the swing speedsetting is selected from among a “high speed,” a “medium speed,” and a“high speed.” The “low speed” is the slowest swing speed and the “highspeed” is the fastest swing speed. The control unit 60 rotates the flapmotor 146 in such a manner as to swing the horizontal flap 144 at aspeed corresponding to the selected swing speed setting.

The swing modes are for determining whether or not the horizontal flap144 will be swung or how it will be swung. There are three swing modes:constant speed mode, stationary mode, and comfort mode. In constantspeed mode, the horizontal flap 144 is swung intermittently at aconstant speed. In stationary mode, the horizontal flap 144 is stoppedat a certain point (angle) during mid-swing and held stationary at thatangle. In comfort mode, the swing speed of the horizontal flap 144 ischanged in accordance with the room temperature (details discussedlater). As will be described later, a room occupant transmits thedesired mode to the control unit 60 with the remote control 40. Thecontrol unit 60 controls the swinging of the horizontal flap 144 usingthe transmitted mode.

The remote control 40 is a user-operated device that transmits the roomoccupant's instructions to the air conditioner 1 so that the airconditioner 1 can be operated according to the wishes of the roomoccupant. The room occupant can use the remote control 40 to set thetarget temperature and to select the swing speed and swing mode of thehorizontal flap 144. These instructions are transmitted from the remotecontrol 40 to the control unit 60 and used for control of the variouscomponents. These instructions are also sent from the remote control 60to the RAM 42 and stored in the RAM 42.

The temperature sensor 43 is provided in the indoor unit 2 and serves tomeasure the temperature inside the room. The temperature sensor 43transmits the measured temperature to the control unit 60.

<Operation of the Air Conditioner 1>

The swing control of the horizontal flap 144 during cooling mode anddehumidifying mode will not be described (see FIG. 9). First, thecontrol unit 60 checks which swing mode has been selected (step S201).If the stationary mode has been selected, the control unit 60 does notswing the horizontal flap 144 (step S202). If the constant speed modehas been selected, the control unit 60 sets the swing speed of thehorizontal flap 144 to the “medium speed” (step S203). If the comfortmode has been selected, the control unit 60 determines if the roomtemperature is equal to or above 24 Celsius (step S204). If the roomtemperature is below 24 Celsius, the control unit 60 sets the swingspeed of the horizontal flap 144 to the “low speed” (step S205). If theroom temperature is equal to or above 24 Celsius, the control unit 60sets the swing speed of the horizontal flap 144 to the “high speed”(step S206).

<Characteristic Features of the Air Conditioner>

(1)

With this air conditioner 1, the horizontal flap 144 is swung at “lowspeed” when the room temperature is equal to or above 24 Celsius.Consequently, the sensible temperature experienced by the room occupantsdecreases because the air delivered from the air conditioner 1 contactsthe room occupants for a long period of time during each swing. As aresult, the occurrence of situations in which the comfort level of theroom occupants is degraded is reduced. Meanwhile, the horizontal flap144 is swung at “high speed” when the room temperature is below 24Celsius. Consequently, the sensible temperature experienced by the roomoccupants doesn't decrease too much because the air delivered from theair conditioner 1 contacts the room occupants for only a short period oftime. As a result, the occurrence of situations in which the roomoccupants feel cold is reduced and the occurrence of situations in whichthe comfort level of the room occupants is degraded is reduced evenfurther.

Thus, when the room temperature is 24 Celsius or above, the occupantscan experience a feeling of comfort similar to that experienced with aconventional air conditioner even if the temperature setting of the airconditioner 1 is set somewhat higher. As a result, the electric powerconsumption per unit time can be reduced.

(2)

With the air conditioner 1, a stationary mode in which the horizontalflap 144 does not swing can also be selected. Thus, the direction inwhich the conditioned air is blown can be fixed.

(3)

With the air conditioner 1, a low speed mode in which the horizontalflap 144 is swung at a “medium speed” can also be selected. Thus, thedirection in which the conditioned air is blown can be changed at aconstant speed.

(4)

With this air conditioner 1, the horizontal flap 144 is swung up anddown. Thus, when the horizontal flap 144 is swung upward, it isdifficult for the delivered air to contact the room occupants.Meanwhile, when the horizontal flap 144 is swung downward, it is easyfor the delivered air to contact the room occupants. As a result, thedelivered air can easily be made to contact the room occupants even whenthe indoor unit 2 is installed above the room occupants' heads (on theceiling, an upper part of a wall, or the like).

(5)

With this air conditioner 1, the horizontal flap 144 is swung at “lowspeed” when the room temperature is below 24 Celsius. Thus, the airdelivered from the air conditioner 1 can sufficiently disperse the coolair existing around the room occupants' feet. As a result, overcoolingof the room occupants' feet can be suppressed.

OTHER EMBODIMENTS

(A)

In the previously described embodiment, the control unit 60 sets theswing speed of the horizontal flap 144 to the “low speed” when thetemperature inside the room is equal to or above 24 Celsius. Meanwhile,when the temperature inside the room is below 24 Celsius, the controlunit 60 sets the swing speed of the horizontal flap 144 to the “highspeed.” Instead, it is also acceptable for the control unit 60 to setthe swing speed of the horizontal flap 144 to the “low speed” when thetemperature inside the room is equal to or above 25 Celsius and to the“high speed” when the temperature inside the room is below 23 Celsius.In other words, it is acceptable to make the threshold temperature arange instead of a single temperature.

(B)

In the previously described embodiment, the control unit 60 sets theswing speed of the horizontal flap 144 to the “low speed” when thetemperature inside the room is equal to or above 24 Celsius. Meanwhile,when the temperature inside the room is below 24 Celsius, the controlunit 60 sets the swing speed of the horizontal flap 144 to the “highspeed.” Instead, it is also acceptable to design the system such that aroom occupant can set the threshold temperature used to control theswing speed of the horizontal flap 144.

APPLICABILITY TO INDUSTRY

When an air conditioner in accordance with the present invention isused, the swing speed of the flap is changed according to the roomtemperature and the amount of time the delivered air contacts the roomoccupants during each swing (complete swing including return swing) ischanged according to the room temperature. Therefore, the occurrence ofsituations in which the comfort level of the room occupants is degradedcan be reduced by appropriately setting the room temperatures at whichthe swing speed is changed and the speed values to which the swing speedis changed.

1. An air conditioner comprising: an air delivery unit configured todeliver conditioned air into a room; a flap configured to adjust adischarge direction of the conditioned air delivered from the airdelivery unit; and a control unit configured to execute a first controlto change a swing speed of the flap without changing a swing range ofthe flap in accordance with a detected room temperature.
 2. The airconditioner as recited in claim 1, wherein the control unit is furtherconfigured to execute the first control without detecting solarradiation, the first control including changing the swing speed to afirst swing speed when the detected room temperature is equal to orabove a prescribed room temperature and changing the swing speed to asecond swing speed that is faster than the first swing speed when thedetected room temperature is below the prescribed temperature.
 3. Theair conditioner as recited in claim 2, further comprising a selectingdevice configured to select either the first control or a second controlthat does not change the swing speed of the flap, and the control unitbeing further configured to selectively execute the second control thatdoes not change the swing speed of the flap upon selection of the secondcontrol by the selecting device.
 4. The air conditioner as recited inclaim 3, wherein the selecting device is configured to select one of thefirst control, the second control or a third control that swings theflap at a constant speed at all times, and the control unit is furtherconfigured to selectively execute the third control that swings the flapat a constant speed at all times.
 5. The air conditioner as recited inclaim 4, wherein the flap is horizontally arranged and the control unitis further configured to swing the flap in an up and down direction. 6.The air conditioner as recited in claim 3, wherein the flap ishorizontally arranged and the control unit is further configured toswing the flap in an up and down direction.
 7. The air conditioner asrecited in claim 2, wherein the flap is horizontally arranged and thecontrol unit is further configured to swing the flap in an up and downdirection.
 8. The air conditioner as recited in claim 1, wherein the airconditioner is for a home or office building.
 9. An air conditionercomprising: means for measuring room temperature of a room with the airconditioner installed therein; conditioned air delivering means fordelivering conditioned air into the room; directional means foradjusting a discharge direction of the conditioned air delivered fromthe conditioned air delivering means; and means for changing a speed ofthe directional means without changing a swing range of the directionalmeans in accordance with the room temperature that was measured.
 10. Amethod of controlling an air conditioner comprising: measuring roomtemperature of a room with the air conditioner installed therein;delivering conditioned air into the room from an air delivery unit;controlling a flap downstream of the air delivery unit for adjusting adischarge direction of the conditioned air delivered from the airdelivery unit; and changing a swing speed of the flap in accordance withthe room temperature that was measured without changing a swing range ofthe flap.